High-rotation electrostatic spray

In order to achieve maximum paint utilization, special electrostatic, high-rotation (HR) sprays are increasingly being examined for their specific apphcation potential, which in combination with the (highly conductive) waterborne paint systems also has a particular effect on the design of the entire paint supply system. The use of HR sprays for jpplying the basecoat is also being advanced... 

High-speed rotating atomizers and electrostatic spraying Metallic basecoat 13 670 75 8.93... 

Rotating electrostatic disks and bell spray coating. Rotating spray coaters (80 to 90% TE) rely on centrifugal force to atomize droplets of liquid as they leave the highly machined, knife-edged rim of an electrically... 

Spray coating is used before and after a product is assembled particularly if already assembled and has complex shaped and curved surfaces. Many different types of spray equipment are in use to handle the different forms of paints used. They are classified by their method of atomization (airless, air, rotary, electrostatic, etc.) and by their deposition assist (electrostatic or nonelectrostatic, flame spray, etc.). Spraying techniques may fall into several of these categories. They range from simple systems with one manual applicator to highly complex, computer-controlled, automatic systems. They can incorporate hundreds of spray units. Automatic systems may have their applicators mounted on fixed stands, on reciprocating or rotating machines, on robots, and so on. 

As originally introduced. Electrostatic Bell Process 2 was used primarily with solvent-based coating materials. The bells were rotated at the lowest possible rate consistent with obtaining good atomization of these materials because it was desired that the mechanical forces acting on the sprayed particles be held to a minimum. Rotation rates were on the order of 1800-3600 rpm. With the recent advent of high solids and waterborne materials that are much harder to atomize, it has become necessary to increase the rotation speed of the bells. Most bells used with this system today are rotated at 20,000-30,000 rpm. This Increase does increase the size of the spray pattern emitted from the bell but does not materially decrease the overall transfer efficiency on those applications where the arrangement of the equipment has been made with this fact in mind. 

Basecoats are sprayed in two layers. The first layer is sprayed electrostatically with high-speed rotation bells, the second layer is sprayed with compressed air to achieve proper orientation of the aluminum particles in metallic paints. The basecoat is then dried for 3-5 min in a warm air zone at 40 - 60°C. 

---